Privacy Policy for DualBook

Privacy Policy for DualBook

Last Updated: August 2026

Privacy & Data Safety

100% Private • Local-First • Secure

Welcome to DualBook. Your financial privacy is our core priority. This Privacy Policy explains how we collect, use, and protect your information when you use our mobile application.

1. Secure Private Cloud Sync

DualBook follows a "Local-First" sync policy. All your financial records (income, expenses, stock, etc.) are primarily stored on your device's local storage. To enable secure automated backups and multi-device access, we use an encrypted private cloud provided by Firebase. We do NOT mine, sell, or share your private financial data with anyone.

2. User Account & Authentication (Google Sign-In)

To provide a secure experience and enable seamless data recovery, DualBook requires sign-in via Google Account. When you sign in, we use your Google profile information (Email and Name) solely for identity verification and to link your encrypted financial records to your specific account. This ensures that only you can access your data across different devices and allows for secure automated backups. We no longer use or collect mobile phone numbers for authentication.

3. Log Data

Whenever you use our service, in case of an error in the app, we collect data and information (through third-party products) on your phone called Log Data. This may include your device IP address, device name, operating system version, and the configuration of the app when utilizing our service. This is used strictly for troubleshooting and improving app stability.

4. Cookies

Cookies are anonymous unique identifiers. This service does not use these "cookies" explicitly. However, the app may use third-party code and libraries (like Google AdMob) that use "cookies" to collect information and improve their advertising relevance and service quality.

5. Service Providers

We employ trusted third-party companies to facilitate our service:

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Google Play Services: For core app functionality.

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Firebase (Google): For secure authentication and encrypted cloud sync.

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Google AdMob: To keep our professional features free for everyone. These third parties have access to technical identifiers only to perform specific tasks and are obligated not to disclose or use them for any other purpose.

6. Connectivity Disclosure

DualBook allows you to view all existing records and reports perfectly in offline mode. However, an active internet connection is mandatory to add new transactions, edit, or modify records. This requirement ensures app integrity, real-time security validation, and data consistency between your device and secure cloud backup.

7. Security

We value your trust in providing us your information, thus we are striving to use commercially acceptable means of protecting it. We use industry-standard encryption to protect your data during transmission and at rest in the cloud. However, remember that no method of electronic storage or transmission over the internet is 100% secure.

8. Links to Other Sites

This service may contain links to other sites (like advertisements). If you click on a third-party link, you will be directed to that site. Note that these external sites are not operated by us; therefore, we strongly advise you to review their Privacy Policy.

9. Data Backup & Recovery

In addition to our Firebase sync, the app utilizes Android Auto Backup, which may sync your local data to your personal Google Drive account in an encrypted format. This backup is private between you and Google; the developers have no access to your private files.

10. Account & Data Deletion (Mandatory)

You have full control over your data. You can permanently delete your account and all associated data (both local records and cloud backups) at any time using the "Delete Account & Data" feature within the app's settings. Once confirmed, your Google account link is removed and all your data is wiped permanently from our servers and cannot be recovered.

11. Children's Privacy

These services do not address anyone under the age of 13. We do not knowingly collect personally identifiable information from children under 13. All data is managed based on the authenticated Google account holder's identity.

12. Changes to This Policy

We may update our Privacy Policy from time to time. You are advised to review this page periodically for any changes. Any updates are effective immediately after they are posted on this page.

13. Contact Us

If you have any questions regarding this Privacy Policy or your data safety, please contact our support ecosystem at: luminexy.dev@gmail.com